This invention pertains to tanks for storing and dispensing fluids, and in particular, to such tanks which are mounted on vehicles.
Dust control can be a particular problem on construction sites, building demolition sites, excavation sites and mine sites. For example, in a mining operation, the mine haul roads essentially consist of dirt and gravel. Dust control is necessary on the haul roads so that the operators of the mine vehicles can readily see the other mine vehicles using the roads. Thus, dust control on the haul roads is a safety issue. Moreover, dust clouds caused by vehicles operating on the haul roads can adversely impact air quality potentially creating environmental issues particularly where the dust clouds drift beyond the mine site.
Typically, mines have water tanker trucks, which are used to water down the haul roads in order to control dust. Such water tanker trucks generally have a plurality of spray nozzles positioned on either the forward or rearward sections of the vehicles to dispense a fluid spray or mist onto the ground. The water tanker truck can also have hoses or a water monitor/cannon for washing down other mining equipment and, in some cases, fire control.
Because of the service demands on such water tanker trucks, they are typically capable of carrying very large quantities of water. For example, water tanker trucks used in mining operations can have fluid capacities of over 50,000 gallons. Of course, vehicle stability is a critical issue when transporting large volumes of water that, in the case of a 50,000 gallon tank, can carry a water load of over 200 tons. Specifically, surging and wave motion of the fluid, particularly transverse surging resulting from centrifugal forces experienced during turning of the truck can cause a tanker truck to become unstable or even to overturn. To prevent such surging of the fluid, the tank is provided with internal baffles.
To ensure a long-life, the interior of the tanks must undergo periodic maintenance. For example, to protect against corrosion, the interior surfaces of the tank may need to be periodically sandblasted and re-coated with a rust protection coating such as an epoxy. This work is complicated by the fact that the tanks only have points of entry on the top of the tank and often just a single point of entry, and thus the work is subject to confined space safety regulations. Accordingly, workers performing tasks inside the tank must be provided with secondary air sources from outside the tank. This can greatly complicate the maintenance operations. Moreover, it can be difficult for the workers to maneuver around the internal tank baffles particularly since the interior of the tank is very dark. Accordingly, maintaining the interior of these tanks can be a difficult and time-consuming process.
Another problem with these types of tanks is that at larger sizes they can be difficult to ship to the location at which they are installed onto the vehicle, typically an off-highway truck. For instance, the largest tanks can be over twenty feet wide. As can be appreciated, transporting a tank of that size can be a difficult and expensive operation.
Accordingly, in view of the foregoing, a general object of the present invention is to provide an improved baffled tank for a tanker truck such as used for dust control in mining operations, construction sites and the like.
A more specific object of one embodiment of the present invention is to provide a tank for such a tanker truck which has an improved baffling system.
Another object of one embodiment of the present invention is to provide a baffled tank for such a tanker truck which is configured so work inside the tank can be performed much more easily.